Abstract. In this article I argue that vanity, the desire for and delight in the favorable opinion of others, plays a fundamental role in Hume's account of moral motivation. Hume says that vanity and virtue are inseparable, though he does not explicitly say how or why this should be. I argue that Hume's account of sympathy can explain this alliance. In resting moral sentiment on sympathy, Hume gives a fundamental role to vanity as it becomes either a mediating motive to virtue or else strengthens the otherwise weak motive of moral sentiment.